car alarm/remote start trouble shooting

I have a CA 610 (code alarm). I installed this remote start alarm with the help of a friend over 2 years ago. Worked like a champ untill recently. I also added some accuaters since its in a car that did not have power locks at the time of the initial install. The car is a 1992 Chevy Lumina Euro (sedan).

The problem atm is the running Tail lights will not come on except for the pulse flash from arming/disarming the alarm. I can not continue to drive with no Tail lights this time of year since I drive to work when its still dark outside. Where and how should I test to find the short. Sorry for my ignorance, I am very new to alarms/remote starts. This was my 1 and only install and about 60% of it was done by a friend who is no longer around. I have installed Countless Stereo systems and work in the IT field. I have all the tools needed to do the job but am stuck finding the problem.

My first thought was a bad relay. I replaced both Relays in the system. Still as soon as I turn on the running lights I blow a fuse and loose all interior and tail lights, But if I arm/disarm the alarm those lights do pulse as normal. What is a good place to start and how exactly do i use the voltage meter to find the short?

attached below is the wiring diagram of the car and a link to the alarm manual.

http://webappshttp.voxdmz.audiovox.com:1025/manuals/installation/CA610Inst_%20revD_122105.pdf

Please help! Thanks in advance for ignoring my newbness.

Yes Ckeeler it is as you described. 1 square button for parking lights 1 square for head lights, and a slider to set how bright the dash lights are.

When the fuse blows the dash lights also go out. Everything works fine till I turn on the parking lights, As soon as I hit that button the fuse blows.

So should I remove this and trace that wire back to see where its spliced into the brain at? Is my short on this wire? Can I test it with my voltage meter to prove the short? I am going to stop on the way home to buy a headlight bulb to try the suggestion up above.

Thanks alot for helping me here guys, I really gotta stop car pooling with the wife. I miss my Alpine SWX 1243D and the back massage on the ride home its so relaxing ;-P

have you seen this before, whats the best way to get a new one, and what is the part name so when i call a junk yard I dont sound like a dumb @$$?

Thanks alot.

its just called a headlight switch assy. it will be the headlight button/parklight button/slider all in one unit, just like you have now. the CARQUEST part number for a new one is DS655. looks like this

Found one on ebay for 22 shipped. Now i play the waiting game.